Mumbai Civic Body Considers Treated Sewage Water for 677 km of Road Washing

Mumbai’s civic administration is considering using treated sewage water to wash roads and reduce dust at a time when the city faces both pollution and water-supply pressure. The Indian Express reported on October 22 that the Brihanmumbai Municipal Corporation was looking at the alternative after a proposal to use water for road sprinkling was stalled by its standing committee. The plan concerns 377 public roads covering roughly 677 kilometres. It is a proposal under consideration, not proof that all those roads have already been washed or that the approach has delivered a measurable air-quality improvement.

Why the earlier plan faced resistance

Road washing and sprinkling are used to keep loose dust from being thrown back into the air by traffic. But the city is also dealing with a reported 10 per cent water-supply cut following deficient rainfall and an early withdrawal of the southwest monsoon. In that setting, elected representatives questioned whether using scarce water on streets was appropriate. The earlier proposal, valued at about Rs 8.13 crore, was stalled. The alternative now being examined is to use water that has already passed through sewage treatment, reducing the need to draw from supplies intended for drinking and household use.

The treatment capacity problem

The report says Mumbai currently has one operational sewage treatment plant at Colaba with a capacity of about 37 million litres a day. The city generates far more sewage than that, so the available treated supply is limited. Seven larger plants are under construction in other parts of the city, with the Bhandup facility expected to become available later. The existence of planned plants does not mean the water is immediately ready for use. For the near term, the city must match road-washing needs to actual treated-water output, distribution arrangements and the quality standards required for the intended purpose.

How the washing drive could work

Civic officials described a plan involving private tankers to transport water and sprinkle roads. The reporting refers to about 29 tankers, each carrying 10,000 litres, and an estimated daily tanker-hiring cost of about Rs 1.45 lakh. Those figures help explain the operational scale, but they do not cover every possible expense or guarantee a final contract value. The proposed 677 kilometres represent about a third of the city’s road network, with areas including Colaba, Worli, Andheri, Ghatkopar, Mulund and the Bandra Kurla Complex. Final routes and timing may change with approval and availability.

What treated water can and cannot do

Using treated wastewater for non-drinking purposes can be a sensible way to conserve freshwater, provided the treatment and handling are appropriate. Road sprinkling can reduce resuspended dust for a period, especially where traffic disturbs fine particles lying on the surface. It does not remove every source of air pollution. Vehicle exhaust, industrial emissions, construction activity and weather conditions still influence air quality. The proposal therefore belongs within a wider pollution-control strategy, not as a substitute for construction-site enforcement, cleaner transport or reliable monitoring.

Questions about public safety and transparency

Residents have a reasonable interest in the quality of water used on roads, the way tankers are filled and the conditions under which sprinkling takes place. The civic body should make clear that treated wastewater is not drinking water and explain what safeguards prevent accidental exposure or misuse. It should also publish the routes, contractor responsibilities and complaint channels if the plan goes ahead. These are practical governance questions rather than evidence of an existing safety failure. A credible programme needs both environmental benefits and public confidence in how it operates.

How to judge whether the idea works

A useful evaluation would compare dust and air-quality readings before and after washing at representative locations, while accounting for traffic and weather. It would also track water use, cost per kilometre, complaints and whether the activity causes unnecessary road disruption. If the city merely counts tanker trips, residents may learn little about whether exposure has fallen. A targeted approach could prioritise roads with documented dust problems rather than spreading limited water too thinly. Officials should explain the criteria they use and update them as monitoring data changes.

Why water reuse is attractive to cities

Large cities produce wastewater every day, even during periods when reservoirs are under pressure. Treating some of that water to an appropriate standard can create a supply for landscaping, industrial uses or street maintenance without drawing the same amount from potable reserves. However, treatment plants, storage, transport and monitoring all cost money. Reuse is not free water. Mumbai’s proposal illustrates how infrastructure decisions made years earlier can limit what is possible today: a single available treatment plant provides far less flexibility than a network of functioning facilities.

The environmental trade-off

Road washing can make sense where dry dust is repeatedly lifted by traffic, but poorly timed spraying may waste water or create slippery conditions and congestion. The city will need to decide when washing is useful and when street sweeping, construction controls or other measures provide better value. Officials should also consider where runoff goes after washing and whether treated water is suitable for the intended contact with roads and drains. These are design questions, not established failures of the proposal. The best outcome would combine dust control with water conservation and a clear public record of results.

The decision still ahead

The latest reporting describes consideration of a treated-water option after the earlier spending proposal faced objections. Approval, procurement and actual implementation remain separate steps. Residents should look for an official schedule and confirmation of water sources before assuming the drive has begun across Mumbai. The wider story is a difficult municipal trade-off: the city wants to control dust without using more of the freshwater households need. Whether treated sewage water becomes an effective part of that response depends on careful execution and transparent results.